1. Field
The present disclosure relates generally to manufacturing and, in particular, to manufacturing composite parts. Still more particularly, the present disclosure relates to a method and apparatus for preparing elongate inserts for use in manufacturing composite parts.
2. Background
Aircraft are being designed and manufactured with greater and greater percentages of composite materials. Some aircraft may have more than fifty percent of their primary structure made from composite materials. Composite materials may be used in aircraft to decrease the weight of the aircraft. This decreased weight may improve payload capacities and fuel efficiencies. Further, composite materials may provide longer service life for various components in an aircraft.
Composite materials may be tough, light-weight materials, created by combining two or more dissimilar components. For example, a composite may include fibers and resins. The fibers and resins may be combined to form a cured composite material.
Further, by using composite materials, portions of an aircraft may be created in larger pieces or sections. For example, a fuselage in an aircraft may be created in cylindrical sections that may be put together to form the fuselage of the aircraft. Other examples may include without limitation wing sections joined to form a wing or stabilizer sections joined to form a stabilizer.
In manufacturing composite parts from composite materials, cavities may be formed within composite parts. For example, stiffening or reinforcement sections may be formed on composite parts. These stiffening elements may be referred to as stringers. Stringers may have cavities and may be used in various composite parts, such as fuselage sections, wall panels, and/or other suitable parts for reinforcing or providing greater rigidity for those parts.
In creating stringers, a cavity or open space is formed in a composite part. These cavities may be formed using elongate inserts, such as, for example, mandrels or bladders. These elongate inserts may be used to form pressure within a cavity during curing of a stringer. Typically, the elongate inserts are wrapped in a release film to allow for the elongate insert to be extracted from the composite part after the curing process.
The process of wrapping and/or securing these materials around the elongate inserts is performed by human operators. This process may be time consuming. Further, in some cases, the material wrapping the elongate insert may not be properly secured, secured too loosely, and/or have some other problem. These issues may lead to problems with extracting the elongate insert from the cavity after curing of the composite part. In some cases, the material may be left inside the cavity after removing the elongate insert. These situations may not be desirable.
Heat shrink release materials also may be used to cover these elongate inserts. The materials may be placed around the elongate inserts and then treated with heat to provide a tight fit.
Heat shrink materials, however, require the application of heat over the entire distance of the elongate insert. These heat shrink materials also are made to a precise size for each stringer. These materials also may distort a cross section of an elongate insert when the elongate insert takes the form of a bladder. When a rubber mandrel is used as the elongate insert, the heat shrink material also may distort the cross section of this type of elongate insert.
Therefore, it would be advantageous to have a method and apparatus that addresses at least some of the issues discussed above.